As part of the three-year, multimillion-dollar contract, MCI will deploy a mix of Windows NT- and Windows 95-based PCs on some 50,000 desktops and acquire the same number of client licenses for Microsoft's BackOffice server applications.

The deal also includes some 40,000 copies of the software giant's Office Professional software and deployment of thousands of copies of Microsoft Internet Explorer browser. They are also working together to build the infrastructure needed to deploy the Exchange Server email engine, the companies added.

The contract sprung from a long working relationship, according to the companies. In the past, MCI participated in Microsoft's Exchange Server early adopter program. And Microsoft will continue the working relationship by helping to staff MCI's Call Center with experts skilled in installing and maintaining the software.

MCI plans to develop user profiles for its work force and deploy software according to specific needs. For example, the sales staff will receive mobile computing tools, while call center representatives will have added security software on their desktops.